Whither the weeds?

Climate change is likely to expand the reach of some of the West's least favorite plants -- for example, see "Bonfire of the Superweeds," HCN's story on invasive buffelgrass in the Sonoran Desert. But a new study in Global Change Biology paints a somewhat more hopeful picture: Scientists predict that some invasive species, such as spotted knapweed and cheatgrass, will simply shift northward in coming decades, abandoning parts of their old territory and so creating opportunities for restoration. Of course, climate change may make it impossible to restore many native plants to these freed-up habitats -- so what would restoration really mean? "The question for policy makers and land managers is, 'What do we want these lands to be?'" comments Princeton University ecologist David Wilcove, one of the study's authors. "These lands will change, and we must decide now -- before the window of opportunity closes -- whether we do nothing or whether we intervene." To tinker or not to tinker -- more and more, that's the dilemma confronting conservation.